// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_SINK_CACHE_H_
#define CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_SINK_CACHE_H_

#include <string>

#include "content/common/content_export.h"
#include "media/base/output_device_info.h"

namespace url {
class Origin;
}

namespace media {
class AudioRendererSink;
}

namespace content {

// Caches AudioRendererSink instances, provides them to the clients for usage,
// tracks their used/unused state, reuses them to obtain output device
// information, garbage-collects unused sinks.
// Thread safe.
class CONTENT_EXPORT AudioRendererSinkCache {
public:
    virtual ~AudioRendererSinkCache() { }

    // Creates default cache, to be used by AudioRendererMixerManager.
    static std::unique_ptr<AudioRendererSinkCache> Create();

    // Returns output device information for a specified sink.
    virtual media::OutputDeviceInfo GetSinkInfo(
        int source_render_frame_id,
        int session_id,
        const std::string& device_id,
        const url::Origin& security_origin)
        = 0;

    // Provides a sink for usage. The sink must be returned to the cache by
    // calling ReleaseSink(). The sink must be stopped by the user before
    // deletion, but after releasing it from the cache.
    virtual scoped_refptr<media::AudioRendererSink> GetSink(
        int source_render_frame_id,
        const std::string& device_id,
        const url::Origin& security_origin)
        = 0;

    // Notifies the cache that the sink is not in use any more. Must be
    // called by the client, so that the cache can garbage-collect the sink
    // reference.
    virtual void ReleaseSink(const media::AudioRendererSink* sink_ptr) = 0;

protected:
    AudioRendererSinkCache() { }

    DISALLOW_COPY_AND_ASSIGN(AudioRendererSinkCache);
};

} // namespace content

#endif // CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_SINK_CACHE_H_
